categorylabelgenerator.java

jfreechart安装程序和使用说明

/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2004, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library is free software; you can redistribute it and/or modify it under the terms
 * of the GNU Lesser General Public License as published by the Free Software Foundation;
 * either version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this
 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 *
 * ---------------------------
 * CategoryLabelGenerator.java
 * ---------------------------
 * (C) Copyright 2001-2004, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * $Id: CategoryLabelGenerator.java,v 1.1 2004/08/31 14:36:24 mungady Exp $
 *
 * Changes
 * -------
 * 13-Dec-2001 : Version 1 (DG);
 * 16-Jan-2002 : Completed Javadocs (DG);
 * 26-Sep-2002 : Fixed errors reported by Checkstyle (DG);
 * 24-Oct-2002 : Method now specifies category index (DG);
 * 05-Nov-2002 : Replaced reference to CategoryDataset with TableDataset (DG);
 * 21-Jan-2003 : TableDataset merged with CategoryDataset (DG);
 * 10-Apr-2003 : Changed CategoryDataset --> KeyedValues2DDataset (DG);
 * 01-May-2003 : Added generateValueLabel(...) method (with a plan to renaming this interface
 *               to reflect its more general use) (DG);
 * 09-Jun-2003 : Renamed CategoryToolTipGenerator --> CategoryItemLabelGenerator (DG);
 * 13-Aug-2003 : Added clone() method (DG);
 * 12-Feb-2004 : Removed clone() method (DG);
 * 15-Apr-2004 : Moved generateToolTip() method into CategoryToolTipGenerator interface (DG);
 * 11-May-2004 : Renamed CategoryItemLabelGenerator --> CategoryLabelGenerator (DG);
 */

package org.jfree.chart.labels;

import org.jfree.data.category.CategoryDataset;

/**
 * A <i>category item label generator</i> is an object that can be assigned to a 
 * {@link org.jfree.chart.renderer.category.CategoryItemRenderer} and that assumes responsibility for 
 * creating text items to be used as labels for the items in 
 * a {@link org.jfree.chart.plot.CategoryPlot}. 
 * <p>
 * To assist with cloning charts, classes that implement this interface should also implement
 * the {@link org.jfree.util.PublicCloneable} interface.
 */
public interface CategoryLabelGenerator {

    /**
     * Generates a label for the specified item. The label is typically a formatted version of 
     * the data value, but any text can be used.
     *
     * @param dataset  the dataset (<code>null</code> not permitted).
     * @param series  the series index (zero-based).
     * @param category  the category index (zero-based).
     *
     * @return the label (possibly <code>null</code>).
     */
    public String generateLabel(CategoryDataset dataset, int series, int category);
    
}